Bt GM crops aren't very insect reststant

September 2014



Bt brinjal (aubergine) protest. CC photo Joe Athialy on Flickr

Is the biotechnology industry vision of perfect GM crops, untouched by pests, falling apart?

Is the grand US vision of its GM technology saving farmers in developing countries getting shaky?

Reports coming from around the world in suggest the dreams are not all they're cracked up to be.

Supertoxic remedies for superweeds

September 2014



Common pigweed. CC photo from Wiki Commons

American farmers have a problem: their crops are drowning in a sea of weeds and their machines are choking to death.

 

In desperation, Texas cotton growers recently petitioned the Environment Protection Agency (EPA) to allow 'emergency' use of propazine, a weed-killer widely banned because it causes birth defects, is an endocrine disruptor, a possible carcinogen, ends up in waterways and takes years to breakdown. Fortunately for the public and the environment, the petition was denied. But how did we come to such a pass?

Germany demands GM-free animal feed

September 2014



Photo by Greenpeace

In April 2013, four major UK supermarkets announced, in concert, that their poultry products would no longer come from livestock fed GM-free feed [1].

The move followed a direct approach to supermarkets from one large soya supplier which had decided to discontinue its non-GM soya line. This was shortly followed by an appeal to retailers from major farmers' representatives for a lifting of the ban on GM feed. The reasons given were cost and a shortage of supplies.

The 'GM helps climate change' myth unravels

September 2014



Fertiliser applied to no-till field in US.
CC photo By Lynn Betts [Public domain], via Wikimedia Commons

In contrast with the traditional ploughing-under of weeds before the sowing of seeds, no-till agriculture involves destruction of weeds on the surface then planting of seeds in grooves or holes with minimal disturbance to the soil.

There are several recognised benefits of no-till. In particular, valuable soil structure is preserved, reducing erosion and increasing important biological activity, plus the retained plant-matter holds more water. For the farmer, no-till means reduced labour and fuel costs.

Also, because breaking up the soil by ploughing triggers a loss of the carbon locked up by soil organisms, no-till has become part of the solution to climate change (see below).

Fit as a weed

September 2014

 

Wild rice. CC photo by Denrdoica cerulea on Flickr

The vast majority of GM crops now being grown commercially have had a gene inserted to make them resistant to glyphosate herbicide.

 

After spraying with glyphosate, the yield of the GM crop is protected because the weeds competing for nutrients are killed.

 

Gene escape from glyphosate-tolerant crops into wild relatives has never been considered an important problem because unless the wild GM derivatives are sprayed with the herbicide, they will have no special fitness advantage and no reason to run riot. But, this 'wisdom' has been challenged by a team of Chinese scientists.

 

Glyphosate kills plants by inactivating an enzyme, 'EPSPS'*. EPSPS is vital to a number of key metabolic processes because it's responsible for generating a class of essential amino acids (the building block of proteins). These amino acids are vital to the formation of, for example, the plant's supportive material (lignin), plant growth hormone, and a huge range of immune-system substances, which together can account for as much as 35% of a plant's biomass. 

GM mosquito tricks get cleverer

September 2014


Aedes aegypti mosquito. CC photo by Sanofi Pasteur on Flickr

Mosquitoes aren't human food. But humans are food for mosquitoes.

 

As mosquitoes feed off you, they inject saliva into you to keep their food (your blood) flowing out. During this, they can also transmit diseases such a malaria and dengue, and the latest thing in GM mozzies can also give you a dose of destructive DNA. 

 

Natural mosquitoes are part of a serious health problem. GM mozzies could be much worse.

Risk avoidance made easy

September 2014

Crop spraying. CC photo by Tamina Miller on Flickr

Risk-assessment of a substance is carried out by examining all the inherent dangers posed by it, and factoring in how likely it is that anyone will actually be exposed to these dangers.

 

A risk-assessment obviously can't be done without looking at the real-life context in which the substance is used.

 

Glyphosate herbicide, widely used on GM crops, is very safe as these things go, providing you're not a plant or a micro-organism.

 

This fact seems to have been exploited by German assessors when they recommended the re-approval and increased 'Acceptable Daily Intake' of the herbicide earlier this year [1].

A preposterous approval

September 2014


Crop spraying. CC photo by CropShot on Flickr

Glyphosate herbicide (see below) has just been re-approved for use in the EU along with a 67% increase in its 'acceptable daily intake' (ADI).   

The report submitted to the European Food Safety Authority (EFSA) recommending re-approval and upping the ADI was prepared by Germany, the rapporteur Member State for this herbicide.
 

Germany's overall findings were that the herbicide poses no unacceptable risks.  Specifically, glyphosate is not metabolised (chemically changed by the body) nor accumulated in the body.  It's not toxic to genes, nor carcinogenic, nor endocrine disrupting, and has no reproductive toxicity.  The only human health risks noted were that glyphosate is a severe eye irritant. 
 

Issues that could not be finalised included the relevance of impurities and microbial effects. 
 

The Institute of Science in Society described these conclusions as 'preposterous'.